I'm heavily invested in time for the Java 1.4. I'm sure many others are like me. Since I'm not a full-time programmer and I have 1.4 materials, I'll finish the Java 1.4 test.
If you are new to study, then you should go for the Java 1.5. Don't waste your time on the older test.
If you work with the 1.4 and are comfortable, then why not certify 1.4.
Hope this helps.
(check out the slick if statements)